Scrolling pages on a computer has been problematic for many years. The traditional method of scrolling on a computer has been through the use of scroll bars. Using this method, a user must position the cursor on the scroll bar, typically located on the side or the bottom of the computer screen, and click on a designated area of the scroll bar. Doing so moves the image on the screen in the direction indicated based on location of clicking on the scroll bar. Alternatively, the user may position the cursor on directional arrow buttons associated with the scroll bar to move the screen image in smaller increments.
However, a scroll bar is designed to be narrow so as to not take up excessive space on a computer screen. Thus, a user must exercise great care and manual dexterity to position the cursor on the narrow scroll bar. Due to such constraints in the size and location of the scroll bar as well as the limitations of the ergonomics of the hardware itself, the user may often fail to precisely move the cursor to the right point on the scroll bar thereby clicking in an improper location. This might lead to either scrolling in an improper and undesired direction or no scrolling at all. The problem of achieving the proper positioning of the cursor on the scroll bar is greatly worsened if the user is using a system in which movement of the cursor is less precise. Examples of such a system include laptop computers or Tablet PCs.
For example, on a Tablet PC, hand positioning is often sub-optimal. A user must exercise skill in accurately positioning the cursor at the proper position on the scroll bar. If the proper position is not achieved, the result is not what is expected, leading to great frustration of the user. For example, it is often difficult for a user to manipulate a stylus pen on a Tablet PC or to utilize a touch tablet such that the stylus pen or user's touch contacts the precise point on a contact surface (e.g., tablet) corresponding to positioning a cursor on the desired point on a scroll bar. If the user inadvertently fails to touch the contact surface (e.g., with the hand, stylus pen, etc.) in an area corresponding to the correct point on the scroll bar, an unexpected and undesired outcome results (e.g., scrolling in the wrong direction or not scrolling at all).
Attempts to simplify scrolling include the use of tools for panning. These panning tools, such as the “hand tool” in Adobe Acrobat Reader®, provide an alternative method of scrolling pages on a computer screen. Using the hand tool, a user may click onto the active area of the computer screen and drag the page in the desired direction as if “grabbing” the page and physically moving the page. This approach provides scrolling or panning capability on non-interactive PDF files but has great limitation in scrolling interactive pages, e.g., web pages.
When attempting to scroll pages with interactive content, for example, the hand tool would likely be effective in scrolling the pages only if the interactive elements are not directly encountered. However, if the user desired to interact with the interactive elements or content on the page, the hand tool would be unable to do so. For example, if while scrolling or panning a web page the user desired to activate a hyperlink on the web page, the user would have to first change the hand tool to a selection tool before being able to activate the hyperlink. Likewise, if the user wished to interact through activation of Javascript/DHTML, the user would have to first change the hand tool to a selection tool. This might necessitate selecting a different tool in the tool box followed by returning the newly selected tool/cursor to the location of the desired interactive content. Pausing scrolling to re-select a new tool is inconvenient to the user.
In some prior art methods, the hand tool is made to automatically convert to a selection tool when the cursor hovers over a hyperlink. Although such a solution may enable a user to avoid having to manually change tools from the hand tool to a selection tool in order to activate a hyperlink, for example, users would be frustrated if the hand tool happens to fortuitously hover over the hyperlink but the user still desires to scroll. In such a scenario, the hyperlink would be unexpectedly activated even though the user did not intend to launch the hyperlink. This would result in frustration for the user because the user would have to spend extra time and effort to return to the prior document to resume scrolling.
Scrolling a page on a computer is also problematic if the page is very large. For example, a web page might be very long such that a user would have to expend large amounts of effort in order to reach a desired point on the web site. Using prior art scrolling methods such as the “hand tool” in Adobe Acrobat Reader®, the user would have to either repeatedly click and drag with the hand tool of the prior art over and over again or face the problems of positioning the cursor on the scroll bar and navigating to the desired location on the web site. Either way, the user would only be able to reach the desired location on the web site after a great expenditure of large amounts of time and energy.
Also, scrolling using the traditional prior art hand tool or scroll bar often results in an unpleasant scrolling experience for the user because of the unevenness of scrolling. Specifically, the scrolling action may be rough and stilted. Such sudden starts and stops of scrolling resulting from the sudden cessation of scrolling when the input device, such as the mouse or the stylus pen, is deactivated by either releasing of the mouse button or lifting of the pen can cause great discomfort and uneasiness in the user.
Thus, a need exists in the art for a system and method for achieving effective scrolling or panning of an electronic document or page such that interactive elements within the document or page may be seamlessly activated while scrolling if desired without the problems associated with having to deselect the panning function. A need also exists in the art for optimizing scrolling or panning of pages on a computer over long distances and for making the scrolling action more natural to the user in terms of inertia of motion of the page.